Currently, the capacity of transferring and processing information through space is limited by the number of bits that can be carried by a single photon in a light beam having a nonzero orbital angular momentum. Generally, the number of orthogonal states of the orbital angular momentum of a photon determines the number of bits that can be carried by the photon. However, generating, detecting, and studying high-order beams (e.g., Bessel beams with an orbital angular momentum that exceed 104 h per photon) that could significantly increase the number of bits that can be carried by a single photon is not easily achievable.
Known techniques for studying orbital angular momentum of light beams include interferometric and holographic methods. These methods either require that many photons in the same state or are designed to study only a selected momentum state. The interferometric technique for measuring orbital angular momentum utilizes a series of cascaded Mach-Zehnder interferometers with rotating elements, such as Dove prisms. This technique classifies the incoming photons by their angular momentum and then directs the classified photons into their corresponding output ports. In the interferometric technique, however, the number of the cascaded Mach-Zehnder interferometers increases with the value of the maximum angular momentum of the photon. As a result, the need for a large number of interferometers for high-order Bessel beams makes this technique impractical.
Accordingly, a need exists for a system, device, and method to efficiently generate, detect, and study high-order Bessel beams. In particular, a need exists for a device that is capable of measuring both single photon and multiple-photon orbital angular momentum states.